1. Field of the Invention
The invention relates to a liquid crystal display (LCD) panel, and more particularly, to an LCD panel that has a repair line structure with a lower RC delay.
2. Description of the Prior Art
In a thin film transistor (TFT) LCD panel, a plurality of thin film transistors, which are formed in a matrix, are in combination with appropriate electric components, such as capacitors and binding pads, to drive liquid crystal pixels to produce a beautiful image. Because TFT LCD panels are small, have a light weight, consume less power, and do not produce radiation, TFT LCD panels are widely used in many portable information products, such as notebooks and PDAs, and replace the traditional CRT monitors of personal computers.
An ordinary TFT LCD panels contains an upper substrate with a color filter, a lower substrate, and a liquid crystal material filled between the upper substrate and lower substrate. The lower substrate has a plurality of scan lines (also called gate lines) thereon and a plurality of data lines (also called signal lines) thereon perpendicular with the scan lines. At the intersection of each of the scan lines and data lines are set at least a thin film transistor for use as a switch device of a pixel. On the lower substrate are further formed a plurality of repair lines for serving as replacing wires to send a signal to every thin film transistor correctly when there is a disconnection on a data line.
Please refer to FIG. 1, which is a schematic structure of an LCD panel 10 according to prior art. As shown in FIG. 1, an LCD panel 10 contains a substrate 12, an X-axial printed circuit board (X-board) 14 and a Y-axial printed circuit board (Y-board) 16, and a flexible printed circuit board (FPC) 29 for electrically connecting the X-board 14 and the Y-board 16, wherein the X-board 14 and the Y-board 16 are used for transmitting signals to the substrate 12 to enable the LCD panel 10 to produce images. The LCD panel 10 further contains a plurality of tape carrier packages (TCPs) 18 for electrically connecting the X-board 14 and the substrate 12, and a plurality of TCPs 20 for electrically connecting the Y-board 16 and the substrate 12. Each TCP 18 or 20 contains an integrated circuit (IC) chip (not shown in FIG. 1).
The substrate 12 has a plurality of scan lines S1-Sm thereon and a plurality of data lines D1-Dn thereon perpendicular with the scan lines S1-Sm. The scan lines S1-Sm and the data lines D1-Dn are used for defining a plurality of pixels (not shown in FIG. 1) formed in matrix in an active region 26 on the substrate. Each of the scan lines S1-Sm is electrically connected to its corresponding TCP 20 through a bonding pad 24, and similarly, each of the data lines D1-Dn is electrically connected to its corresponding TCP 18 through a bonding pad 22. The substrate 12 further contains at least a repair line 28. The repair line 28 is set on the X-board 14, Y-board 16, and the substrate 12 for repairing the data line D1-Dn on the substrate 12 when there is a disconnection on a data line D1-Dn. The method of repairing a data line is described below.
Please refer to FIG. 2, which is a schematic diagram of a method using a repair line to repair an LCD panel 10 according to prior art. If a disconnection occurs at the point A of the data line Dn, the prior art method uses a laser welding to connect the terminals point B and C of the data line Dn with the repair line 28. Therefore a signal will pass through the path 30 to every pixel when the X-board 14 outputs a signal to the data line Dn.
According to the prior art, the repair line 28 transversely crosses data line D1-Dn, so it will cause an RC delay effect on the repair line. As a result, the effect of the RC delay will be greater when the size of the LCD panel 10 becomes larger and the RC delay will cause the distortion of the image signal on the panel finally. Therefore, how to distribute and set the repair line on the X-board, Y-board, or the substrate to reduce the RC delay becomes a main issue for improving the yield of manufacturing an LCD panel with a large size.
It is therefore a primary objective of the claimed invention to provide an LCD panel that has a repair line with a lower RC delay to solve the above-mentioned problem.
According to the claimed invention, the LCD panel contains a first substrate, at least two first printed circuit boards, and at least a repair line. The first substrate has a plurality of first conductive wires thereon, and the first conductive wires are arranged in parallel with each other along a first direction. Each of the first printed circuit boards is electrically connected to the first substrate respectively for outputting signals to the first conductive wires. In addition, the repair line contains a first portion positioned on the first substrate, a second portion positioned on each of the printed circuit boards, and a third portion positioned on a connective region located between each of the first printed circuit boards.
It is an advantage of the claimed invention that the LCD panel contains a connective region so that the repair line on each of the first printed circuit boards is capable of being connected in the connective region, wherein the connective region is set on the substrate, a flexible printed circuit (FPC), which electrically connects each of the first printed circuit boards, or a control board. If the connective region is set on the substrate of the LCD panel, the amount of the connectors for connecting two adjacent first printed circuit boards and the effect of the RC delay on the repair line will both be reduced. If the connective region is set on the FPC or a control board, the advantage is that the manufacturing process can be simplified.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.